Green, slimy, deee-licious, the avocado is probably the blandest foodstuff that my daughter eats. I first gave her it as a finger food proper (not a great success - it shot out of her hand and proved impossible to pick up - cue tears of frustration) but now she gets it on toast or a  rice cake. I take one out with us to the park and I eat half of it on bread (doused in lemon juice and buckets of salt, it's a heart attack waiting to happen) while the bub has some plain.
 
Some people think they are a pain to open up but the secret is to slice it in half lengthways and twist it (not unlike the peach) leaving you with one side open and the other still containing the stone. The spiffy thing with the avocado is that if you doink the knife into the stone it will lift straight out. Does not work with a peach, as I found out to mine and the NHS's cost.

This creepy, furry orange fruit is one of my daughter's favourites... bleurgh. Thank god it has a fairly short season.
Wash it, cut it in half, remove the stone and hand to child with the skin side facing outwards. Actually, they're not bad to take out to cafes etc with you as they fit quite nicely into those silly wee tupperwares and can be cut open with a normal knife. But they do ripen quickly and get very squishy very fast so time it right or everyone will get covered in orange mush.

My favourite food ever, and now my baby's... I'm so very proud.
I just wash it, half it across the stone, and twist sharply so that the halves come apart then cut into quarters and remove the stone. She used to grab my hand when I was eating peaches so we first started with me holding it and her sucking/biting on it but it didn't take long for her to want to take it herself.

I've noticed that it's easier to give the baby the peach quarter with the skin side facing outwards as she seems to go at it from underneath with her rather marvellous brand new TWO TEETH. My cup runneth over...

Anyway, all I'm saying it that it might be worth noting which side your baby prefers to have the skin side facing. To be honest I was a bit paranoid about her eating the skin to begin with but apart from a couple of bleary-eyed spit-ups she was absolutely fine. Keep an eye on it, though. If we see a worryingly large bit of food going in, my husband and I start making hilarious puking faces, sticking our tongues out, crossing our eyes and whatnot (it's veeeeery attractive) and she normally laughs and spits it out.